It seems like the parents have crossed the moral event horizon and we're getting a "disowning the gay daughters" arc, except both kids should now be fine without them. Mashiro should have at least one job remaining, enough to pay rent, and Makino would probably be motivated enough to work part time if it means living with Mashiro while dating. Even if she doesn't get a part time job, she basically just needs food and can share study resources with Mashiro, who will likely continue to tutor her. Then she can just be a student when she gets into university. Her sister was already independent of course.
The parents are definitely going to regret this I think, but are stubborn enough that it may take them a while to admit their mistakes. They were not violent or anything though, so I continue to maintain they do care about their daughters and do not want to actually sever all ties with them. Like with a lot of parents, maintaining control, maintaining social image, and the child's well being kind of get merged into the concept of "for your own good", which can lead to them taking actions concerning the child for selfish reasons without realizing it.